Boron nitride has a BN formula, in which a boron atom and a nitrogen atom form a two dimensional hexagonal structure. Since this structure is a similar hexagonal-based structure to that of graphite, boron nitride has similar chemical and physical properties to graphite, and thus is a material having highly physical and chemical stabilities. In an inactive atmosphere, boron nitride is stable at up to 3000° C., has thermal conductivity as high as that of stainless steel, thereby having a high thermal shock resistance, and is not cracked or damaged even if it is repeatedly subjected to rapid heating at approximately 1500° C. or rapid cooling. In addition, boron nitride has very excellent high temperature lubricating property and corrosion resistance. In addition, since boron nitride has a significantly high electric resistance value and less change in the electric resistance value, particularly at a high temperature, it may be used as an electric insulating material in a wide temperature range, and emits UV rays when an electric field is applied. Moreover, boron nitride is transparent and has excellent flexibility due to space margin of a hexagonal honeycomb structure in which boron atoms and nitrogen atoms are linked in the form of a network. Specific structure and physical properties of such boron nitride may be applied to an insulator of a semiconductor material and a UV radiator.
Recently, as demands and concerns on nanotechnology are increased, research to obtain boron nitride in a type of a nanosheet or nanotube is progressing. Currently, as a method of manufacturing a hexagonal boron nitride nanosheet, mechanical peeling, chemical vapor deposition (CVD), or a boron nitride interlayer compound method is used, and generally, the CVD and mechanical peeling are used for manufacturing a hexagonal boron nitride nanosheet.
The mechanical method is a method of detaching a single-layered or multi-layered boron nitride of a hexagonal boron nitride in a solvent through ultrasonic wave treatment. According to this method, it is simple to manufacture but difficult to mass-produce a hexagonal boron nitride nanosheet. The CVD method is a method of forming a thin metal film by depositing a catalyst metal on a substrate and cooling the film after a gas including boron and nitrogen flows at a high temperature of 1000° C. or more, thereby obtaining a boron nitride nanosheet formed on the metal film. According to this method, a process temperature is very high, and thus it is difficult to obtain a larger and less expensive boron nitride nanosheet.